textproduct: Quad Cities

KEY MESSAGES

- A dry and pleasant day is in store for the Labor Day holiday. No impactful weather is expected.

- Hot and humid conditions will return on Tuesday with near- advisory heat indices in far southeast Iowa and northeast Missouri.

- A band of showers and storms is expected Tuesday afternoon through Wednesday. Isolated severe storms will be possible with this activity Tuesday evening through Wednesday morning. Heavy rainfall may lead to flooding issues over northeast Iowa Tuesday night.

SHORT TERM /THROUGH TONIGHT/

Issued at 251 AM CDT Mon Sep 7 2026

Temperatures have fallen into the 60s and low 70s this morning as we sit just to the east of the ridge. This has maintained a dry airmass across the area, as seen by widespread dewpoint depressions of 2-8 degrees. Due to this, chances for fog early this morning are slim. The best chances (10-20%) for isolated areas if fog are across northwest Illinois, where dewpoint depressions are lowest.

After the low-end potential for fog through a couple hours after daybreak, yet another above normal early September day is in store for the holiday today. Scattered cloud cover will help limit temperatures slightly, resulting in highs in the upper 70s to mid 80s from north to south. Additionally, breezy easterly winds with gusts of 10-20 mph will further contribute to a pleasant but warm Labor Day.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 251 AM CDT Mon Sep 7 2026

Past Monday, a pattern change is in store as a trough advances across the northern Plains into Canada. This will bring us multiple weather concerns of heat, thunderstorm chances, and heavy downpours Tuesday and Wednesday.

As the midlevel ridge collapses eastward, low level winds will turn southerly to southwesterly, advecting in warm and moist air late Monday night through Tuesday. While temperatures will be hot, with Tuesday's highs in the mid 80s to mid 90s, heat indices will not be as oppressive as last week's heat due to the potential for showers and storms throughout the day. At this time, heat indices are expected to remain below headline criteria over much of the area, with only parts of northeast Missouri and far southeast Iowa having moderate chances of exceeding heat indices of 100 degrees (20-60%).

Across the northern half of the area, rainfall and thunderstorm potential will be a greater concern than heat. Multiple waves associated with the northern Plains/southern Canada trough will pass across the area Tuesday and Wednesday, leading to multiple rounds of rain. While some showers will be possible (15-30%) Tuesday morning, the bulk of the rainfall will occur Tuesday afternoon through Wednesday as a cold front slowly sags through the region. While the timing remains consistent across much guidance, rainfall totals do not. NBM 1-inch exceedance probabilities over 48 hours are low at 20- 50%. However, shear parallel to the front suggests that training thunderstorms will be possible, leading to the potential for more localized heavy rain. CAM guidance has caught onto this potential, as can be seen in the REFS's 1-4 inch 24-hour rainfall north of Interstate 80 in Iowa. While recent dryness may help limit widespread flooding concerns, heavy rainfall could lead to a localized flooding threat. As a result, WPC has issued a Slight, level 2 of 4, risk for flash flooding for Tuesday.

In addition to the potential for training, convective parameters suggest that there is some potential for isolated severe storms overnight Tuesday through Wednesday morning. Due to a more multicellular storm mode, damaging winds and large hail will be the primary threats. SPC has issued a Marginal, level 1 of 5, risk for severe thunderstorms.

On Wednesday, showers and storms will slowly exit the area as the cold front pushes through. Model trends have shown this slowing down, with some not having the front exit until late Wednesday evening or even Thursday morning. As a result, Wednesday, while still hot, will begin the transition to another period of cooler but above normal temperatures. Flow aloft will also become more zonal once the front moves out, though multiple impulses will lead to additional chances for showers, storms, and some heat towards the weekend.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 611 AM CDT Mon Sep 7 2026

A mix of clear skies to the east and a VFR mid-level stratus deck to the west were observed as of TAF issuance. The stratus deck is expected to scattered out with time late this morning into the afternoon hours, with winds turning more southeasterly with time. Winds should remain around 10 knots through the end of the TAF period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.